Actuation gear for a ratchet wrench



Aug. 26, 1969 c. scuu. 3,463,038

ACTUATION GEAR FOR A .RA'ICHET WRENCH 7 Filed June 1, 1967 5 Sheets-Sheet 1 2 l o o v 1.

/ FIG'. I.

/ INVENTOR.

LOUIS c. SCULL FIG. 2

ATTORNEY 6) l7 W 0 w Aug. 26, 1969 L. c. scuu.

ACTUATION GEAR FOR A RATCHET WRENCH 3 Sheets-Sheet 2 Filed June 1, 1967 FIG. 4

INVENTOR. LOUIS C. SCULL ATTORNEY g- 26, 1959 L. c. scuu. 3,463,038

ACTUATION GEAR FOR A RATCHET WRENCH Filed June 1, 19s? 3 Sheets-Sheet s v INVENTOR. LOUIS C. SCULL WXW ATTORNEY United States Patent 3,463,038 ACTUATION GEAR FOR A RATCHET WRENCH Louis C. Scull, 3019 Garnet Lane, Apt. A, Fullerton, Calif. 92631 Filed June 1, 1967, Ser. No. 642,795 Int. Cl. B25b 17/02 US. Cl. 81-581 1 Claim ABSTRACT OF THE DISCLOSURE A circular member having teeth along its inner circumference for meshing with the teeth of the pinion gear which has fewer teeth so that a favorable gear ratio between the two members results. By virtue of the mechanical advantage thus developed, a workpiece can be operated on by manually rotating the circular member digitally.

BACKGROUND OF THE INVENTION Field of the invention The invention relates to an actuation gear for a ratchet Wrench and, more particularly, to such a gear having teeth along its inner circumference for meshing with teeth of a smaller pinion gear connected to the extension of the wrench.

Description of prior art Patent No. 2,982,161 teaches one embodiment of a ratchet wrench having a minimum number of moving parts and includes a pawl arrangement for controlling the direction of rotation of the pinion gear. A control disc is connected to the pawls for changing the direction of the awls and, therefore, the direction of rotation of the pinion gear. The pinion gear is connected to a shaft which engages a socket. As a result, the work engaging member can be caused to rotate in either a clockwise or a counter-clockwise direction. No provision is shown for incorporating an initial actuation gear into the wrench.

That such a capability is needed is shown by Patent No. 2,982,160 for a spinner drive means for a ratchet Wrench. As indicated in the referenced patent, an attachment is provided for facilitating the initial actuation of a nut or stud by the wrench although the initial actuation is directly connected to the stud or nut actuation element.

The patent characterizes the prior art as comprising ratchet wrenches having a handle at one end, a coupling element in the form of a stud or socket rotatably mounted at the other end by a form of ratchet. Since the ratchet must be capable of transmitting the maximum torque which the operator can assert by means of the handle, the pawl and ratchet or equivalent mechanism must be of standard construction using a spring sufficiently strong to insure permanent and sure engagement of the pawl with the ratchet.

In starting a bolt or stud in a threaded opening, the nut or stud may be relatively loose so that initial engagement of the nut or stud in the opening is relatively difficult. Engagement of the parts does not develop adequate frictional resistance to prevent the bolt or stud from becoming unscrewed when the ratchet of the wrench is operated. Some means must be provided, therefore, to tighten up the element before the ratchet wrench can be used.

The referenced invention provides a manually operated means directly connected to the coupling element which can be held or gripped by an operators hand when the 'ice handle is moved in its backward stroke or for rotating the coupling member in a desired forward direction while holding the handle with the other hand.

However, the only advantage in such a device is that a knurled, relatively large circular member is provided which can be manipulated by the hand. No mechanical advantage is incorporated into such device and the same relative resistance to turning is present.

Patent No. 2,462,729 teaches a manipulating member for a socket wrench which enables the socket engaging portion of the wrench to be manually manipulated by the fingers of the user. The knurled disc is connected directly to the socket engaging portion. The patent does not teach a means for providing a mechanical advantage by using the manipulating member. In other words, the disc is directly connected so that no gear ratio between the disc and the socket engaging member is possible. Other art may be seen by referring to Class 81, Subclass 58.1.

SUMMARY OF THE INVENTION Briefly, the invention comprises a ratchet wrench including a handle means connected to a housing member in which a coupling member is disposed. The coupling member may be described as a pinion gear to which a shaft is connected. The shaft projects orthogonally from the housing and includes a portion to which sockets can be engaged. Pawl means is connected to the side of the pinion gear means opposite the area of meshing between the teeth for engaging the teeth when the handle of the ratchet wrench is actuated for causing angular rotation of the projecting member in response to a force applied to the other end of the handle. The pawl permits the handle to be moved in the opposite direction without applying a force to the projecting member.

The inventive element comprises a digitally operable circular member having teeth along its inner circumference. In one embodiment, the housing may partially enclose the member while in other embodiments the member may have a diameter which exceeds the length and width of the housing means. The member has teeth along its inner circumference for mating with the teeth along the outer circumference of the pinion gear. The circular member is provided with a larger number of teeth for developing a mechanical advantage by virtue of the gear ratio between the two members.

In certain embodiments, one end of the handle may be detachable from the end comprising the coupling member so that an operator can have greater access to the actuation gear.

Therefore, it is an object of this invention to provide a ratchet wrench having an improved actuation gear.

It is still another object of this invention to provide a ratchet wrench in which actuation gearing means provides an operator with a mechanical operating advantage.

Still another object of this invention is to provide a ratchet wrench having an actuation gear which permits an operator to initially tighten or loosen a workpiece in an engaged position without the necessity for rotating the handle.

Another object of this invention is to provide an improved ratchet wrench for use in areas of restricted operating space.

Still another object of this invention is to provide an improved ratchet wrench for use under circumstances wherein the workpiece must be engaged in the securing area digitally by hand before the ratchet wrench can be used.

These and other objects of this invention will become more apparent in connection with the following drawings.

3 BRIEFDESCRIPTION OF THE DRAWINGS FIGURE 1 shows one embodiment of a ratchet wrench using an enclosed actuation gear.

FIGURE 2 shows an exploded view of the FIGURE 1 embodiment.

FIGURE 3 shows a second embodiment of a ratchet wrench having a portion of the actuation gear extending from the housing.

FIGURE 4 shows a side view of the FIGURE 3 embodiment.

FIGURE 5 shows a third embodiment of the ratchet wrench having the external circumference of the actuation gear extending from the housing.

FIGURE 6 shows a side view of the FIGURE 5 embodiment.

FIGURE 7 shows an exploded view of an embodiment similar to the FIGURE 5 embodiment.

FIGURE 8 shows a different embodiment actuation gear having a larger circumferential edge.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGURE 1 shows ratchet wrench 1 comprising handle means 2 terminating at one end in housing means 3. The housing means partially encloses the remaining portions of the wrench.

Spur or pinion gear 4 is disposed within the housing means so that shaft projects through opening 6 of the housing. The shaft projects at approximately a right angle to a horizontal plane through the longitudinal axis of the body of the wrench. One end of the shaft is provided with socket holder portion 7 to which sockets may be connected. The gear portion has a diameter relatively larger than the opening so that the gear remains within the housing.

Pawl means 8 is connected inside the housing means by means of a control level 9 having a length sufficient to engage the pawl to the housing at one end. At the other end the level is provided with handle portion 9 which can be gripped by an operator for changing the position of the pawl with respect to gear means 4. The lever is rigidly connected to the pawl. Depending on the position of the pawl means with respect to the gear, the gear can be rotated in either a clockwise or counterclockwise direction. The pawl is disposed under the ring gear and engages the pinion gear at a different part of its relatively long axis.

The pawl may be spring loaded by spring means comprised of a spring and ball bearing or other means well known in the art so that when it is in a position with respect to the pinion gear, the spring tends to restore it after a movement. In other words, the pawl in the embodiment shown, includes teeth at the termination thereof adjacent to the pinion gear. The teeth of the pinion gear contact the teeth of the pawl in one direction of rotation of the pinion gear, and cause the pawl to be displaced by the movement of the pinion gear. The displacement is proportional to the size and configuration of the teeth of the pinion gear. The spring force acting on the pawl causes it to remain in contact with the teeth of the pinion gear. In other words, one edge, or in certain embodiments, one tooth of the pawl is forced into contact with the rotating teeth of the pawl. The pawl is permitted to be displaced as the tooth of the pawl rides along the incline of the teeth of the pinion gear.

When the rotation of the pinion gear is reversed, the teeth of the pawl and the teeth of the pinion gear mesh and the gear is prevented from additional rotational movement. In that position, the ratchet wrench, through the shaft and the socket (not shown), connected to the socket holder, operates on a workpiece. The force applied to the handle is transmitted through the control lever and the pawl to the pinion gear which is directly connected 4 to the socket holder. For example, a nut or bolt might be loosened or tightened in a threaded hole by virtue of the torque applied through the wrench.

In the first position, that is when the pawl and pinion gears are rotatable with respect to each other, the handle of the ratchet wrench is rotated to a position for applying a torque to the workpiece. -When the handle is being rotated into such a position, it is desired that the socket holder remain fixed in its position. Otherwise, the torque previously applied by the wrench would be at least partially cancelled out. The holder may be held in place by means of actuation gear 10.

The initial actuation gear 10 is circumferentially disposed about the pinion gear. The actuation gear may be also described as a ring gear having teeth disposed along its inner circumference. The teeth mesh with the teeth of the pinion gear along the circumference of the pinion gear opposite to the circumference disposed adjacent to the pawl. Obviously, the teeth of the ring gear are greater in number than the teeth of the pinion gear so that a mechanical advantage results. A relatively slow rotation of the ring gear results in a relatively rapid rotation of the pinion gear. Similarly, a relatively small force such as that possible with the fingers, transmits a relatively increased force to the shaft connected to the pinion gear. Various sizes of ring and pinion gears with various teeth ratios can be used, although it would be required to disassemble the wrench and replace both members when a different ratio is desired. Mechanical ratios within the range of from 2 to 1 to 5 to 1 are possible.

In the FIGURE 1 embodiment the ring gear may have a maximum diameter equal to or less than the width of the housing of the wrench. In other embodiments, however, the diameters may have different relative sizes. As a result, knurled disc 11 is connected to cover portion 12 on the ring gear through shaft 13. The disc may be connected to the shaft by means of a screw or other engaging devices.

Cover plate 14 is disposed over the completed assembly and is held in place by the protruding ends of flexible member 16. The cover plate prevents the parts from falling from the housing when the wrench is in an inverted position.

A more detailed view of wrench 1 is shown in FIG- URE 2 wherein the embodiment is illustrated in an exploded view. The connection of the knurled disc to the ring gear cover is more clearly illustrated. In addition, the interconnection between the ring gear and the pinion gear can be more clearly seen. Bottom cover plate 17 may be removed to permit assembly of the pawl inside the housing.

FIGURE 3 shows a top view of a second embodiment of the ratchet wrench illustrated in FIGURE 1. Handle portion 30 terminates in housing portion 31. Ring gear 32 includes teeth along its inner circumference. The teeth of pinion gear 33 mesh with the teeth of the ring gear. Pawl 34 is shown in a position for permitting the handle to be rotated in a clockwise direction prior to applying torque to the pinion gear in a counter-clockwise direction. Lever 35, connected to the pawl, may be rotated in a counter-clockwise direction in order to provide a capability for applying torque in a clockwise direction. Spring means 40 is also shown contacting one edge of the pawl for forcing the pawl into contact with the pinion gear.

The primary difference between the FIGURE 1 and FIGURE 3 embodiments is that the maximum diameter of the ring gear in FIGURE 3 exceeds the width of the housing portion so that the knurled disc is not required. An operator can rotate the ring gear by gripping the knurled edges of the outer circumference where the circumference protrudes from the housing portion.

The ring gear also includes circumferentially disposed channel means 36 adjacent to the lower portion of the housing portion. The housing may be provided with a raised portion (not shown) which inserts into the channel and holds the ring gear in place. The raised edge would prevent radial movement of the ring gear with respect to the housing portion.

FIGURE 4 shows a side view of the FIGURE 3 embodiment. It can be seen that the housing portion encloses the ring gear on two sides and leaves it exposed on the other sides so that an operator can grip the edges. Portion 37 of the cover may be partially hollowed to permit the pawl and pinion gear to operate. The hollow portion is not visible in FIGURES 3, 4, 5, 6, 7, 8 or 9 although it should be obvious to those skilled in the art. Cover portion 38 encloses and retains the members within the housing portion. The cover can be attached to the housing portion by attachment means such as screws, etc. well known in the art. It should be pointed out in connection with all the figures that although the cover is not shown flush mounted, the various parts can be increased or deceased so that the assembled parts are flush mounted. In other words, there will be little or no space between the parts such as the cover and ring gear in FIGURE 4. A lubricant may be inserted in the housing to reduce friction.

FIGURE 5 shows a third embodiment of the ratchet wrench in which the maximum diameter of ring gear 60 exceeds the length and width of housing portion 61 (see FIGURE 6) so that an operator can grip the knurled edges of the ring gear at any location about its circumference. The figure also shows pinion gear 62, pawl 63, spring means 64, and shaft 65 comprising other portions of the wrench.

FIGURE 6 shows a cross sectional view of the FIG- URE 5 embodiment in which channel portion 39' along the bottom surface of the ring gear and raised edge 43 of the housing are more clearly illustrated. Cover portion 41, which may be connected to the housing portion by attachment means such as screws, etc., as previously described, is shown in position over the ring gear so that the combination of the cover and the raised edge inside the channel prevents the ring gear from becoming displaced from the wrench. Portion 42 may be partially hollow to permit assembly of the pawl 44, spring 45 and pinion gear 46 to be assembled inside the ring gear. The wrench also includes pinion gear pawl, control level shaft and ratchet holder a previously described for the other embodiments.

FIGURE 7 shows an exploded view of an embodiment similar to the FIGURE 5 embodiment except that the FIGURE 7 embodiment is shown with detachable handle 48. In certain applications it may be desired to detach the handle so that an operator can more easily operate on a workpiece such as in areas of very restricted space. The fingers on one hand could grip body portion 49 of the embodiment, while the fingers of the other hand rotate ring gear 50 and cause a workpiece to be rotated in one direction or the other.

As shown in FIGURE 7 the wrench comprises the body or housing portion 49 and includes raised edge 51. Detachable handle 48 is shown connected to the housing portion by means of threaded insert 52. The housing means includes opening 53 into which shaft 54 is inserted.

The housing also includes opening 55 into which a portion of level 56 is inserted.

FIGURE 7 also shows cover means 57 having appropriate openings 58 and 58' therein for accommodating attachment means such as screw threaded means 49 and opening 59 for accommodating the lever. The additional opening 70 provides a means for connecting pinion gear 71 to the top portion of shaft 54. Lever 56 inserts into the opening in pawl 72 and is rigidly secured, for eX- ample, by making the body of the lever rectangular and by making the opening in the pawl rectangular. A similar connection could be used for the pinion gear and shaft 54. Ring gear is also shown as having teeth along its inner circumference and as having a knurled external circumference. The diiference is numbers of teeth between the pinion gear and the ring gear are clearly illustrated thereby showing the mechanical advantage to be obtained by using the ring gear. Operation of the device is as previously described. The ring gear includes channel 73 along its bottom surface for mating with raised edge 51. The channel and raised edge provide a means for holding the ring gear in place. Additional details are not believed to be necessary.

Referring now to FIGURE 8 wherein is shown a different embodiment of ring gear 74. The FIGURE 8 embodiment comprises a modification of the FIGURE 7 embodiment. In effect, the outer edge of the ring gear comprises raised portion 75 which encircles cover 76. The circumferentially disposed raised portion provides a substantially increased area which may be gripped by an operator. The cover is provided with a protruding circumferentially disposed portion 77 which inserts into channel 78 of the ring gear. The engagement is on top of the ring gear instead of above the bottom surface as shown in FIGURE 7. In other respects the embodiment is identical to the FIGURE 7 embodiment and for that reason other details have been omitted.

Although the invention has been described and illustrated in detail, it is to be understood that the same is by way of illustration and example only, and is not to be taken by way of limitation; the spirit and scope of this invention being limited only by the terms of the appended claim.

I claim:

1. A ratchet wrench having a housing, said wrench comprising a pinion gear rotatably secured in said housing, a ring gear having teeth along its inne circumference and having a radius relatively larger than the radius of the pinion gear, said ring gear being mounted on said housing for having its teeth mate with the teeth of said pinion gear along one circumference of said pinion gear,

a pawl gear disposed adjacent to a different circumferential portion of the pinion gear for permitting the pinion gear to be rotated in one direction and for restricting motion of the pinion gear in the other direction, said ring gear being circular and having its outer circumference extending beyond the housing of the ratchet wrench whereby an operator can grip the outer circumference of the ring gear and cause the pinion gea to rotate,

said housing having a raised edge, said ring gear having a circular channel along one of its surfaces for mating with the raised edge of said housing, said raised edge being inserted into said circular channel for restricting radial motion of the ring gear, a cover disposed over said ring gear and connected to said housing for holding the ratchet wrench together.

References Cited UNITED STATES PATENTS JAMES L. JONES, Ire, Primary Examiner U.S. Cl. X.R. 81-57 

